The present invention relates generally to the field of marking systems and, more specifically, to a scribe and/or dot peen stylus technology for automated marking.
The scribe and dot peen styluses used in automated marking are replaceable tools used to place markings on objects by deforming the surface of the object. When a scribing system is used, the tip of the stylus is first caused to contact the surface of the object by mechanical, rather than manual (hand or other human limb), means. Mechanical means includes, without limitation, a solenoid, air cylinder, or other mechanical means that can displace physical objects along lines and/or curves in two and/or three dimensions. Once the tip of the stylus engages the surface, the stylus is then dragged along the surface for a predetermined distance to generate the desired mark. The terms “drag”, “dragged”, “drug”, and any derivatives thereof are defined herein to mean maintaining contact between the scribing tip of the scribe stylus and the surface to be marked while the scribing tip of the scribe stylus is displaced relative to the surface along one or more lines and/or curves while a force is applied to the scribe stylus sufficient to seat the tip against the surface and cause markings in the surface where the scribing tip makes contact. The stylus is then removed from the surface. The steps of the tip contacting the object's surface and applying a force, dragging, and removing the tip from the surface are repeated until the desired surface markings are generated.
For dot peen marking the stylus is caused to contact the surface of the object by mechanical, rather than manual (hand or other human limb), means with sufficient force to make a mark. Mechanical means includes, without limitation, a solenoid, air cylinder, or other mechanical means that can displace physical objects along lines and/or curves in two and/or three dimensions with sufficient force to deform the surface at the point of impact. Once the tip of the stylus engages the surface and makes a mark, the stylus is then removed from the surface. This process is repeated, thereby leaving one or more indentations on the surface without dragging the tip against the surface.
Neither stylus is intended to remove substantial material to make the markings, but rather the stylus modifies the surface, such as by deforming the material at the surface adjacent the tip. Nevertheless, an insubstantial amount of material may be removed during the act of scribing, even though material removal is not the intended or primary means of marking. Thus, stylus marking is to be distinguished from machining or engraving, in which the primary mode of marking is by intentionally removing material from the substrate by a high speed, and typically rotating, bit or tool. The application of scribing is not typically considered as mechanically demanding as machining, engraving, and/or other metal working processes, because little to no material is removed by either stylus during scribing. Furthermore, the relative velocity of the stylus to the surface being marked is substantially lower during the dragging portion of scribing than the relative velocity of machining tools, such as a lathe cutting bit or drill bit during the marking portion of engraving or machining. However, as scribing speeds increase and the number of parts marked per tip increases, so does tip wear and the total number of impacts the tip sustains. Likewise, the continual impact in dot peen marking is very demanding on the tip material, especially with deeper marks and the use on harder substrate materials. As the use of scribed and dot peen markings increases, so will the need for more advanced styluses.
The process of dot peening and the process of contact, dragging and removal is repeated over and over to modify the surface for many objects, including identification markings such as text, pictures, and barcodes. Many scribe and dot peen styluses suffer from premature failure and short lifetimes due to the rigorous circumstances such styluses are subjected to. Scribe styluses are driven in a variety of methods to make initial contact, and then are dragged across the material's surface to leave markings, as is described in U.S. Pat. No. 7,191,529, which is incorporated herein by reference. Dot peen styluses are driven in a variety of methods to make contact with the material's surface and leave markings, as described in U.S. Pat. No. 4,506,999 and U.S. Pat. No. 5,316,397, which are incorporated herein by reference.
Current state of the art scribes and dot peen styluses that have single crystal diamond tips, as described in U.S. Pat. Nos. 7,926,184; 6,671,965; and 7,191,529, are used for marking on hard substrates where more traditional materials like cemented tungsten carbide or tool steel would fail rapidly and leave poor quality marks. These styluses are made by brazing a single crystal of diamond onto the tip. The braze has some chemical means of attachment, but the diamond is predominantly held in place by braze material that envelopes the diamond, thus providing a mechanical grabbing or enclosing of the crystal as described in U.S. Pat. No. 3,138,875. Because of the containment mechanism, these styluses have a tendency to break upon repeated impacts, pull out of the stylus, and wear rapidly when used to form markings on hard surfaces, such as on ferrous metals and titanium. This results in costly down time, repairs, damaged materials, and the possibility of unmarked parts.
Therefore, it can be seen that there is a need for an improved scribe and dot peen styluses that are tougher, wear slower, and resist pullouts.